Suzuki GSF400 Spark Plug
GarageDex's powersports data shows the Suzuki GSF400 uses a CR8EIX spark plug, gapped to 0.032".
Spark plug fitment by year
| Years | Standard plug | Iridium upgrade | Gap |
|---|---|---|---|
| 1978-1979 | - | CR8EIX | 0.032" |
400cc motorcycle. Match the exact part code, thread reach, and heat range. The iridium column is the same-fit upgrade for a longer service life.
Spark plugs for your Suzuki GSF400
The recommended plug is a CR8EIX. Match that code - spark plugs are thread-, reach-, and heat-range-specific, so the part number matters more than the brand. Worth considering: the CR8EIX iridium upgrade - it fits the same port, fires cleaner, and lasts far longer between changes.
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Frequently asked
What spark plug does a Suzuki GSF400 take?
GarageDex's powersports data shows the Suzuki GSF400 uses a CR8EIX spark plug, gapped to 0.032".
What is the spark plug gap on a Suzuki GSF400?
The Suzuki GSF400 spark plug gap is 0.032". Set the gap with a feeler gauge before install - iridium plugs come pre-gapped but always verify, since a wrong gap causes misfires and hard starts.
How often should I change the spark plugs on a motorcycle?
Standard plugs typically want replacing every 8,000-12,000 miles (or per your service manual); iridium plugs go much longer. Fouled or worn plugs cause hard starts, misfires, and poor fuel economy - a cheap part that punches above its weight.